U.S. Pat. No. 4,617,085 describes a method for removing organic material from an organic film by ablative photodecomposition using ultraviolet light of wavelength 193 nanometers from an ArF excimer laser. The rate of removal is said to be substantially enhanced by the use of polymer blends or copolymers in which aliphatic vinyl polymer units such as acrylates or methacrylates, are present together with aromatic vinyl polymer units having pendant aromatic rings, such as styrenes, vinyltoluenes or vinylbiphenyls.